FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person * CAZALOT CLARENCE P JR   2. Issuer Name and Ticker or Trading Symbol MARATHON OIL CORP [MRO] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) President and CEO (Last) (First) (Middle) C/O MARATHON OIL CORPORATION, 5555 SAN FELIPE ROAD 3. Date of Earliest Transaction (Month/Day/Year) 03/03/2005 (Street) HOUSTON, TX 77056 4. If Amendment, Date Original Filed(Month/Day/Year) 03/07/2005 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price COMMON STOCK 03/03/2005   M   47,500 (1) A $ 23.4063 313,052 D   COMMON STOCK 03/03/2005   S   29,500 D $ 48 283,552 D   COMMON STOCK 03/03/2005   S   5,000 D $ 48.09 278,552 D   COMMON STOCK 03/03/2005   S   3,000 D $ 48.04 275,552 D   COMMON STOCK 03/03/2005   S   1,000 D $ 48.06 274,552 D   COMMON STOCK 03/03/2005   S   6,000 D $ 48.03 268,552 D   COMMON STOCK 03/03/2005   S   3,000 D $ 48.02 265,552 (2) D

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

EMPLOYEE STOCK OPTION (Right to Buy)

$ 23.4063

03/03/2005

M(3)

47,500 (1)

03/03/2003(4)

03/03/2010

COMMON STOCK

47,500

$ 0

252,500

D

STOCK APPRECIATION RIGHT

$ 23.4063

03/03/2005

M(3)

47,500 (1)

03/03/2003(4)

03/03/2010

COMMON STOCK

47,500

$ 0

252,500

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
CAZALOT CLARENCE P JR C/O MARATHON OIL CORPORATION 5555 SAN FELIPE ROAD HOUSTON, TX 77056	X		President and CEO

Signatures

R. J. Kolencik-Attorney-in-Fact for Clarence P. Cazalot, Jr.		03/08/2005
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	This amended Form 4 is being filed to correct the reporting of a stock option exercise and cancellation of a tandem SAR on 03/03/2005 in the amount of 106,000 shares at an exercise price of $22.4063. This stock option exercise should have been reported as an exercise of 47,500 shares and acquisition of the underlying 47,500 shares on 03/03/2005, not 106,000 shares as originally reported.
(2)	This amended Form 4 is also being filed to correct the reporting of a stock option exercise and cancellation of a tandem SAR on 03/03/2005 in the amount of 21,400 shares at an exercise price of $25.50. This stock option exercise and acquisition of the underlying 21,400 shares occurred on 03/04/2005 and will be reported on a separate Form 4.
(3)	Exercise of stock option and cancellation of tandem stock appreciation right.
(4)	Vests in three equal annual installments on March 3, 2003, 2004 and 2005.

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